E-bike kit problem: SW900 and error 9

Hi guys,

I have finally installed my new 1000W 48V e-bike kit with 52V battery and hooked everything up. When I first turned it on and hit the throttle, wheel strarted to spin for 0.5 - 1 sec and then stopped. After that I got "error 9" message on my LCD. I checked the wires and re-connected everything but nothing changed. The battery is currently at 52-53V.

When I turn the throttle I can hear a click coming from the controller - like a relay or something.

I don't know if that's normal but as soon as I connect cables from the motor (4 pcs) to the controller the wheel becomes stiff and it doesn't rotate normally - it feels like someone's holding a break gently. When I disconnect these wires it starts rotating normally.

Also, when I was connecting the power cables from the battery to the controller there was some sparking. Next time I connected the wires there was no sparking at all.

Any ideas what might be the problem? I hope I haven't fried something (controller or motor).
Every suggestion is welcome.

Forgot to mention, I was soldering new connectors to the controller since the ones that came with it and with the battery didn't match (red and black cable). Could I've done some damage to the controller if I was overheating the cables with a solder iron? I'm grasping at straws here...

While I don't have the BBSHD, I had an Error 9 and I had burned out my controller. It sounds like you have a manufacturer's defect. I would write your seller and get a replacement.

It's not a BBSHD, it's a rear wheel motor kit from Voilamart: https://www.amazon.com/Voilamart-Electric-Conversion-Intelligent-Controller/dp/B079T25XCN/ref=sr_1_2?ie=UTF8&qid=1537529117&sr=8-2&keywords=voilamart+1000w&dpID=51Ueix00EFL&preST=_SY300_QL70_&dpSrc=srch

I'll open the controller later today to see if I can see any obvious signs of something being fried.
Thanks snowmobile_56308!

4 wires going to motor? Are you counting that 5 wire connector as 1 wire, in addition to the green, yellow, and blue wires?

Sorry, 4 cables. Yes, I count the hall cable with 5 wires as one.

zag0 said:

I don't know if that's normal but as soon as I connect cables from the motor (4 pcs) to the controller the wheel becomes stiff and it doesn't rotate normally - it feels like someone's holding a break gently. When I disconnect these wires it starts rotating normally.

Click to expand...

This is not normal. This is an indication that your motor phase wires are being shorted together. Your idea to open up your controller and inspect and test is a good one. Paying particular attention to the FETs.

Update: I think there's nothing wrong with the motor. I followed this test video and it funtions as expected: https://www.youtube.com/watch?v=Yh9ngpOKS5o

When I connect any two wires together the motor is stiff and when I release them it rotates freely. So I guess that proves the problem is somewhere inside or around the controller.

I'm using a 52V battery, not 48V. Do I have to set something on SW900 for that?

I tried to disassemble the controller but no luck, I guess they used Loctite when screwing the MOSFET heatsink to the aluminum frame. But using the flashlight I see no obvious signs of something being fried on the controller PCB.

As soon as I connect blue wire the wheel becomes stiff. When I unplug it it rotates freely again.

So:
- green connected, yellow connected, blue not connected = moves freely
- green connected, yellow not connected, blue connected = stiff
- green not connected, yellow connected, blue connected = stiff
- all connected = stiff

Looking at this video I see that, when all three wires are connected, the motor should be spinning freely (see 3:10 of the video). In my case it isn't. And even if all three cables are disconnected I get error 9 on the display.
https://www.youtube.com/watch?v=Rh2nCfksh3U

Could it be that blue phase FET's are shortened?

zag0 said:

Could it be that blue phase FET's are shortened?

Click to expand...

Yep, without getting inside the controller housing and testing them this would be my assumption.

Only other possibility I can think of is a few odd controllers out there utilize this as an anti-theft feature. They use an internal set of relays to short two phase wires while the bike is off and in a "alarmed' state. Once the system sees a RFID key or FOB transmitter disarm signal, the relays switch and the intentional short is gone.

I don't think this controller is one of those.

Demand a replacement while you can.

Error 09 is a controller problem per the SW900 manual. And your tests sure prove it.

Ask for a new one.

Thanks guys, I received the replacement controller and bike is now up&running!

One last question:

I tested the battery and top speed and got around 35 km (22 mi) running at top speed of around 46 kmh (28.5 mph). This is without PAS (don't have it on my bike yet), only twist throttle. Since I mostly drive on sidewalks I don't drive at max speed in continuity a lot since I have to avoid people, cross roads, stop at traffic lights etc.

Does this distance/max speed seem right to you? Dunno why but I expected around 50+ km (31+ mi) of range with a 14Ah battery... This is enough range for 2 trips to work and back, meaning I have to charge every other day.

Battery: 52V 14Ah 14S4P Samsung 3.7V 3500mAh 10A cells
BMS: 30A continuous, 70±10A maximum
Motor: 1000W rear hub

Battery bought here: https://www.aliexpress.com/item/US-EU-No-Tax-US-EU-No-Tax-Whale-Electric-Bicycle-Battery-14S4P-52V-14Ah-li/32829580802.html?spm=a2g0s.9042311.0.0.79434c4drpi6yl
Kit bought here: https://www.ebay.co.uk/itm/Voilamart-26-Electric-Bicycle-E-Bike-Conversion-Kit-250W-1000W-Front-Rear-Wheel/112497011093?_trksid=p2485497.m4902.l9144

Hi op, I'm having the same issue.

Did you ever find what caused it?

MaximilianMM said:

Hi op, I'm having the same issue.

Did you ever find what caused it?

Click to expand...

zag0 said:

Thanks guys, I received the replacement controller and bike is now up&running!

Click to expand...